He will do better in at least a 3 gallon tank...5 gallon would be even better. That container of yours is way too small. And along with a larger tank, he needs a heater set to 77 degrees and a filter. A sponge filter or internal filter would be ok. And only feed a few beta pellets per day... over feeding causes water problems.
Walmart sells a nice 5 gallon tank with a hood, light, and filter for $30 delivered to your door. You would just need to add a small heater.